MWA Grand Master Clark (The Shadow of Your Smile) explores identity theft in her middling 30th novel. Almost two years after someone snatched Alexandra "Zan" Moreland's then three-year-old son, Matthew, from his stroller while his sitter dozed, Zan, a New York City interior designer who remains devastated, has been unable to trace her son. To make matters worse, somebody is using her credit cards to purchase expensive items just as she's on the verge of landing a prestigious account for her fledgling business. Worst of all, evidence emerges that suggests Zan kidnapped her own son. Meanwhile, a priest is troubled by a woman whose confession reveals that a murder is being planned. Contrivances that prevent key information from reaching the heroine as well as characters without personality in the service of a plot with at least one major hole won't please those who prefer their suspense firmly grounded in reality and logic. (Apr.)